CVE-2020-11038 : Security Advisory and Response

Integer Overflow to Buffer Overflow in FreeRDP

Understanding CVE-2020-11038

What is CVE-2020-11038?

In FreeRDP version 2.0.0 and below, a vulnerability exists where an Integer Overflow can lead to a Buffer Overflow. This allows a malicious server to manipulate the client to write data out of bounds to an allocated buffer.

The Impact of CVE-2020-11038

This vulnerability can be exploited by a remote attacker to execute arbitrary code on the target system, potentially leading to a compromise of the affected system.

Technical Details of CVE-2020-11038

Vulnerability Description

The issue arises when /video redirection is used, causing the server to instruct the client to allocate a smaller buffer size due to an integer overflow, leading to a buffer overflow.

Affected Systems and Versions

Vendor: FreeRDP
Product: FreeRDP
Versions Affected: <= 2.0.0

Exploitation Mechanism

Attack Vector: Network
Attack Complexity: High
Privileges Required: None
User Interaction: Required
Scope: Changed
Confidentiality Impact: None
Integrity Impact: High
Availability Impact: Low
Base Score: 6.9 (Medium)

Mitigation and Prevention

Immediate Steps to Take

Update FreeRDP to version 2.1.0 or later to mitigate this vulnerability.
Disable /video redirection if not essential to operations.

Long-Term Security Practices

Regularly update software and apply security patches promptly.
Implement network segmentation and access controls to limit exposure to potential threats.

Patching and Updates

Apply the patch provided by FreeRDP in version 2.1.0 to address the Integer Overflow to Buffer Overflow vulnerability.